The race to achieve highest efficiency had engineers turning to innovative topologies and new components such as SiC to take the lead. In parallel, after years of dormancy, old but very innovative ideas such as the mixed-voltage NPC topology have been rediscovered and put to good use in many solar inverter applications.

Surprisingly, all these efforts have focused on the power range up to 100kW, while standard two-level topologies with low switching frequencies continue to dominate in the range beyond 100kW.

The problem is that the extended geometry of high-power applications makes it difficult to avoid parasitic inductance. On top of that, the effect of parasitic components increases linearly with current.

Most designs reduce switching speed to limit the influence of parasitic effects. And true enough, dynamic losses are indeed minimized when the switching frequency is reduced by up to 4kHz.

The new power module design presented here transcends the limitations associated with >100kW power inverters to accommodate high switching frequencies and innovative topologies.

Based on standard Si components, this new solution uses parasitic inductance and applies the fundamentals of power electronics to boost the performance of conventional designs.